Editing Draco Malfoy (section)

===''Harry Potter and the Half-Blood Prince''===
Draco is drawn into Death-Eaters' activities more directly in ''[[Harry Potter and the Half-Blood Prince]]''. Because of Lucius' arrest and fall from Voldemort's favour, [[Narcissa Malfoy]] and [[Bellatrix Lestrange]] visit Snape at his home to discuss a dangerous task that Voldemort has assigned Draco. Narcissa, deeply worried that her son will be killed in his attempt to complete it, begs Snape to make an [[Unbreakable Vow]] to aid Draco with this task and protect him at all costs, and if Draco fails to complete the mission, he will complete it himself; he agrees.

Under the [[Cloak of Invisibility (Harry Potter)|Invisibility Cloak]], Harry, Ron, and Hermione follow Draco to [[Borgin and Burkes]], a dark magic shop in Knockturn Alley. Draco threatens Mr. Borgin about repairing one item and keeping another safe for him. Draco shows Mr. Borgin something on his arm that Harry believes to be the [[Dark Mark]], Voldemort's sign, though whether or not Harry is correct is never confirmed. (In the film version Draco Malfoy shows Dumbledore the Dark Mark on his arm.) On the Hogwarts Express, Harry invisibly spies on Draco and overhears him discussing Voldemort's task with several other Slytherins. Draco knows Harry is present and, once alone in the compartment, immobilises him and breaks his nose causing Harry to hate Draco even more. Harry is left stranded on the train until [[Nymphadora Tonks]] ([[Luna Lovegood]] in the film adaptation) rescues him. Harry spends much of the year trailing Draco's whereabouts on his [[Marauder's Map]], but loses track of him once Draco enters the Room of Requirement. When [[Katie Bell (Harry Potter)|Katie Bell]] is almost killed in Hogsmeade after handling a cursed necklace and Ron nearly dies by drinking poisoned [[mead]], Harry suspects Draco is behind both attacks.

In this book, Draco is, for the first time since being introduced in the series, portrayed as having considerable initiative, ingenuity, and perseverance. However, unlike Harry, who always relies on his friends' support and help, Draco mostly works alone in the Room of Requirement, refusing to confide in or involve his own circle of friends, whom he treats more as underlings. This, and the realisation of what he is ultimately expected to do, nearly drives him to a nervous breakdown. When Harry walks in on Malfoy crying in [[Moaning Myrtle]]'s bathroom, Draco attempts to cast the Cruciatus Curse. Harry is faster to the draw with an obscure ''Sectumsempra'' spell that he learned from the mysterious Half-Blood Prince's book. The spell cuts deep gashes into Malfoy's face and chest, resulting in severe blood loss. Snape, alerted by Myrtle's screams, swiftly arrives and heals Draco's cuts, then takes him to the hospital wing.

Near the conclusion, Draco ambushes and disarms a gravely weakened Dumbledore at the Astronomy Tower. After Draco disarms him, Dumbledore calmly reasons with the frightened teenager and persuades him to reveal how he was, according to Voldemort's orders, to kill the headmaster through the cursed necklace and the poisoned mead. Malfoy reveals that he mended the broken [[Vanishing Cabinet]] in the Room of Requirement to act as a portal enabling Death Eaters to enter Hogwarts. Draco is hesitant to kill Dumbledore and he eventually lowers his wand. Snape arrives, dispatches Dumbledore himself and then flees Hogwarts with Draco in tow. As revealed during his confrontation with Dumbledore, Draco was an insecure boy incapable of committing cold-blooded murder and was forced to do Voldemort's bidding under the threat of his and his parents' deaths. Harry, who was horrified by the result of his duel with Draco in the bathroom incident, feels "the tiniest drop of pity mingled with his dislike" for his old rival.

During an interview in 2005, Rowling revealed that she enjoyed writing Draco in this book, and that the character "did a lot of growing up" as well.<ref name="tlc">{{cite news |title=The Leaky Cauldron and MN Interview Joanne Kathleen Rowling – Part 2 |url=http://www.the-leaky-cauldron.org/2007/07/28/jkrhbp2/ |access-date=9 February 2022 |publisher=[[The Leaky Cauldron (website)|The Leaky Cauldron]] |date=28 July 2007}}</ref>